Changing the appearance of nickel or nickel-plated materials, such as gun parts, through coloration or selective coloration is a desirable method gun owners, manufacturers, hobbyists, and enthusiasts embrace to improve the aesthetics of firearms. Some popular techniques used for coloration, such as “bluing” or “cold bluing”, work well for steel or other ferrous parts but not very well for non-ferrous parts, such as nickel parts and/or Ni-plated parts.
Current methods to change the appearance of Ni-plated materials have therefore been limited to the application of a paint coating, such as commercially available in Cerakote™ coatings, or the application of a physical vapor deposition (PVD) or diamond-like carbon (DLC) coating process. The application of paint offers a variety of colors for the finished product, but does not give a durable finish. PVD and DLC applications provide a very durable and extremely hard surface, but are quite brittle.
“Bluing” or “Cold Bluing” of steel has been well known in the industry for use on ferrous metal parts to provide some corrosion resistance, and a dark, black color. These coloring compounds or solutions are meant to be used on ferrous metals, primarily those alloys with a low chromium and nickel content. These products and the related trade literature consistently warn against their use on nonferrous materials, or those that contain high amounts of nickel.
Accordingly, there is a need to address the aforementioned needs and deficiencies relating to changing the coloration of nickel (Ni) and Ni-plated materials.